U.S. patent application number 17/097173 was filed with the patent office on 2021-03-04 for transcatheter delivery system with wheel actuation.
This patent application is currently assigned to St. Jude Medical, Cardiology Division, Inc.. The applicant listed for this patent is St. Jude Medical, Cardiology Division, Inc.. Invention is credited to Spencer Patrick Brown, David John Copeland, Bruce Edward Frohman, Michael William Metz, Michael Shane Morrissey, Janis Paulis Skujins.
Application Number | 20210059815 17/097173 |
Document ID | / |
Family ID | 1000005222188 |
Filed Date | 2021-03-04 |
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United States Patent
Application |
20210059815 |
Kind Code |
A1 |
Morrissey; Michael Shane ;
et al. |
March 4, 2021 |
Transcatheter Delivery System With Wheel Actuation
Abstract
A delivery device for a collapsible prosthetic heart valve, the
delivery device including an inner shaft, a distal sheath disposed
about a portion of the inner shaft and forming a compartment with
the inner shaft, the compartment being adapted to receive the
prosthetic heart valve, the inner shaft and the distal sheath being
movable relative to one another, and a handle including a frame
having a longitudinal axis, a proximal end and a distal end, the
handle further including a deployment actuator and a hub, each of
the deployment actuator and the hub being independently capable of
opening and closing the compartment, the hub further including a
hub actuator coupled to the inner shaft.
Inventors: |
Morrissey; Michael Shane;
(St. Paul, MN) ; Frohman; Bruce Edward; (Plymouth,
MN) ; Metz; Michael William; (Minneapolis, MN)
; Skujins; Janis Paulis; (Minneapolis, MN) ;
Copeland; David John; (Minnetonka, MN) ; Brown;
Spencer Patrick; (Providence, RI) |
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Applicant: |
Name |
City |
State |
Country |
Type |
St. Jude Medical, Cardiology Division, Inc. |
St. Paul |
MN |
US |
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Assignee: |
St. Jude Medical, Cardiology
Division, Inc.
St. Paul
MN
|
Family ID: |
1000005222188 |
Appl. No.: |
17/097173 |
Filed: |
November 13, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15976282 |
May 10, 2018 |
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17097173 |
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62506251 |
May 15, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F 2/2418 20130101;
A61F 2/9517 20200501; A61F 2/95 20130101; A61F 2/2436 20130101 |
International
Class: |
A61F 2/24 20060101
A61F002/24; A61F 2/95 20060101 A61F002/95 |
Claims
1. A delivery device for a collapsible prosthetic heart valve, the
delivery device comprising: an inner shaft; a distal sheath
disposed about a portion of the inner shaft to form a compartment
with the inner shaft, the compartment being sized to receive the
prosthetic heart valve, the inner shaft and the distal sheath being
movable relative to one another; and a handle including a frame
having a longitudinal axis, a deployment actuator operatively
connected to the distal sheath, and a hub operatively connected to
the inner shaft, each of the deployment actuator and the hub being
independently capable of opening and closing the compartment, the
hub further including a hub actuator coupled to the inner
shaft.
2. The delivery device of claim 1, wherein the deployment actuator
includes a first wheel having an axis of rotation disposed parallel
to the longitudinal axis of the frame, and the hub actuator
includes a second wheel having an axis of rotation that is parallel
to the axis of rotation of the first wheel.
3. The delivery device of claim 2, wherein the second wheel is
engaged with a translating cam having a threaded portion, the cam
being coupled to the inner shaft.
4. The delivery device of claim 3, wherein the cam includes a
flange that is perpendicular to the axis of rotation of the second
wheel.
5. The delivery device of claim 3, wherein the cam is capable of
translating between about 0.050 inches and about 1 inch in a
direction parallel to the axis of rotation of the second wheel.
6. The delivery device of claim 3, wherein the cam is capable of
translating between about 0.25 inches and about 1 inch in a
direction parallel to the axis of rotation of the second wheel.
7. The delivery device of claim 3, wherein rotation of the second
wheel results in longitudinally translating the inner shaft.
8. The delivery device of claim 1, wherein rotation of the
deployment actuator results in longitudinally translating the
distal sheath to cover or uncover the compartment.
9. A delivery device for a collapsible prosthetic heart valve, the
delivery device comprising: an inner shaft; a distal sheath
disposed about a portion of the inner shaft to form a compartment
sized to receive the prosthetic heart valve, the inner shaft and
the distal sheath being movable relative to one another; and a
handle including a frame having a longitudinal axis, a deployment
actuator, a resheathing lock having a lock body coupled to a
protruding lock finger in contact with a compression spring, a lock
arm coupled to the lock finger, and a lock button coupled to the
lock arm.
10. The delivery device of claim 9, wherein the lock button has a
first position disposed within the frame, and a second position in
which the lock button protrudes from the frame.
11. The delivery device of claim 9, wherein the distal sheath is
coupled to a threaded rod, the threaded rod being coupleable to the
lock body.
12. The delivery device of claim 11, wherein the lock body has a
pair of ribs configured to maintain contact with a bottom of the
threaded rod when the threaded rod translates along the
longitudinal axis of the frame.
13. The delivery device of claim 11, wherein the lock finger is
configured to be disposed within a cavity of threaded rod in a
first lock condition that prevents distal movement of the distal
sheath, and to be substantially parallel with the threaded rod in a
second unlocked condition that allows distal movement of the distal
sheath.
14. The delivery device of claim 9, further including a compression
spring coupled to the lock finger.
15. The delivery device of claim 14, wherein the compression spring
is configured to apply a force to the lock body.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a Divisional patent application
of U.S. application Ser. No. 15/976,282 filed May 10, 2018, which
claims the benefit of U.S. Provisional Patent Application No.
62/506,251 filed May 15, 2017, the disclosure of which is hereby
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present disclosure relates to a delivery system for
heart valve replacement and, in particular, for replacement of
collapsible prosthetic heart valves. More particularly, the present
disclosure relates to delivery systems for collapsible prosthetic
heart valves that may be repositioned during the deployment
procedure.
[0003] Prosthetic heart valves that are collapsible to a relatively
small circumferential size can be delivered into a patient less
invasively than valves that are not collapsible. For example, a
collapsible valve may be delivered into a patient via a tube-like
delivery apparatus such as a catheter, a trocar, a laparoscopic
instrument, or the like. This collapsibility can avoid the need for
a more invasive procedure such as full open-chest, open-heart
surgery.
[0004] Collapsible prosthetic heart valves typically take the form
of a valve structure mounted on a stent. There are two types of
stents on which the valve structures are ordinarily mounted: a
self-expanding stent and a balloon-expandable stent. To place such
valves into a delivery apparatus and ultimately into a patient, the
valve must first be collapsed or crimped to reduce its
circumferential size.
[0005] When a collapsed prosthetic valve has reached the desired
implant site in the patient (e.g., at or near the annulus of the
patient's heart valve that is to be replaced by the prosthetic
valve), the prosthetic valve can be deployed or released from the
delivery apparatus and re-expanded to full operating size. For
balloon-expandable valves, this generally involves releasing the
entire valve, assuring its proper location, and then expanding a
balloon positioned within the valve stent. For self-expanding
valves, on the other hand, the stent automatically expands as the
sheath covering the valve is withdrawn.
[0006] In conventional delivery systems for self-expanding aortic
valves, for example, after the delivery system has been positioned
for deployment, the annulus end of the valve is typically
unsheathed and expanded first, while the aortic end of the valve
remains sheathed. Once the annulus end of the valve has expanded,
it may be determined that the valve needs to be repositioned in the
patient's aortic annulus. To accomplish this, a user (such as a
surgeon or an interventional cardiologist) typically resheathes the
annulus end of the valve so that the valve can be repositioned
while in a collapsed state. After the valve has been repositioned,
the user can again release the valve.
[0007] Once a self-expanding valve has been fully deployed, it
expands to a diameter larger than that of the sheath that
previously retained the valve in the collapsed condition, making
resheathing difficult. In order for the user to be able to more
readily resheathe a valve, it is preferable that the valve be only
partially deployed, with a portion of the valve still collapsed
inside of the sheath.
[0008] Despite the various improvements that have been made to the
collapsible prosthetic heart valve delivery process, conventional
delivery devices, systems, and methods suffer from some
shortcomings. For example, in some delivery devices for
self-expanding valves, it is difficult to control how much of the
valve remains in the sheath during a partial deployment, and the
user may accidentally deploy the valve fully before verifying that
the annulus end of the valve is in the optimal position in the
patient's valve annulus, thereby taking away the opportunity to
resheathe and reposition the valve. Moreover, it is difficult
during prosthetic heart valve delivery to determine whether a valve
assembly will function as intended without full deployment of the
heart valve. Due to anatomical variations between patients, a fully
deployed heart valve may need to be removed from the patient if it
appears that the valve is not functioning properly. Removing a
fully deployed heart valve increases the length of the procedure
and increases the risk of infection and/or damage to heart
tissue.
[0009] There therefore is a need for further improvements to the
devices, systems, and methods for transcatheter delivery of
collapsible prosthetic heart valves, and in particular,
self-expanding prosthetic heart valves. Among other advantages, the
present disclosure may address one or more of these needs.
SUMMARY OF THE INVENTION
[0010] In some embodiments, a delivery device for a collapsible
prosthetic heart valve includes an inner shaft, a distal sheath
disposed about a portion of the inner shaft and forming a
compartment with the inner shaft, the compartment being adapted to
receive the prosthetic heart valve, the inner shaft and the distal
sheath being movable relative to one another, and a handle
including a frame having a longitudinal axis, a proximal end and a
distal end, the handle further including a deployment actuator and
a hub, each of the deployment actuator and the hub being
independently capable of opening and closing the compartment, the
hub further including a hub actuator coupled to the inner
shaft.
[0011] In some embodiments, a delivery device for a collapsible
prosthetic heart valve includes an inner shaft, a distal sheath
disposed about a portion of the inner shaft and forming a
compartment with the inner shaft, the compartment being adapted to
receive the prosthetic heart valve, the inner shaft and the distal
sheath being movable relative to one another, and a handle
including a frame having a longitudinal axis, a proximal end and a
distal end, the handle further including a deployment actuator a
resheathing lock having a lock body coupled to a protruding lock
finger in contact with a compression spring, a lock arm coupled to
the lock finger, and a lock cap coupled to the lock arm.
[0012] In some embodiments, a delivery device for a collapsible
prosthetic heart valve includes an inner shaft, a distal sheath
disposed about a portion of the inner shaft and forming a
compartment with the inner shaft, the compartment being adapted to
receive the prosthetic heart valve, the inner shaft and the distal
sheath being movable relative to one another, and a handle
including a frame having a longitudinal axis, a proximal end and a
distal end, the handle further including a deployment actuator, the
deployment actuator being coupled to a clutch mechanism that
permits movement of the distal sheath in a first condition and
impedes movement of the distal sheath in a second condition.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Various embodiments of the present delivery system are
disclosed herein with reference to the drawings, wherein:
[0014] FIG. 1 is a side elevational view of a prior art collapsible
prosthetic heart valve in an expanded condition, showing the valve
assembly attached to the stent;
[0015] FIG. 2A is a highly schematic side elevational view showing
partial deployment of a collapsible prosthetic heart valve with
high placement according to the prior art;
[0016] FIG. 2B is a highly schematic side elevational view showing
partial deployment of a collapsible prosthetic heart valve with low
placement according to the prior art;
[0017] FIG. 3A is side view of an operating handle for a
transfemoral delivery device for a collapsible prosthetic heart
valve, shown with a side elevational view of the distal portion of
a transfemoral catheter assembly;
[0018] FIGS. 3B-D are side and top views of the operating handle of
FIG. 3A, and an enlarged side view of the hub in the proximal-most
position, respectively;
[0019] FIG. 4 is an enlarged perspective view of the carriage
assembly of the handle of FIG. 3A;
[0020] FIG. 5 is an enlarged schematic representation of a portion
of the threaded rod of the carriage assembly of the operating
handle;
[0021] FIG. 6 shows a deployment indicator for use with the
operating handle;
[0022] FIGS. 7A-B are schematic illustrations showing the use of
the operating handle of FIG. 3A;
[0023] FIG. 8A is a schematic illustration showing the use of a
second wheel to close a gap between a distal sheath and a distal
tip of a delivery device;
[0024] FIGS. 8B-C are longitudinal cross-sectional views of the
proximal end of the operating handle of FIG. 3A showing the use of
the second wheel to close the gap between the distal sheath and the
distal tip of the delivery device;
[0025] FIGS. 9A-G are schematic perspective, cross-sectional and
side views of another example of a resheathing lock mechanism;
[0026] FIG. 10A is a schematic exploded view of an actuator having
a clutch mechanism;
[0027] FIG. 10B is a longitudinal cross-sectional view of the
actuator of FIG. 10A;
[0028] FIGS. 10C-D are perspective views of an exemplary drive nut
and clutch plate of the actuator of FIG. 10A; and
[0029] FIGS. 11A-E are schematic perspective, cross-sectional,
front, and side views of another example of a resheathing lock
mechanism.
[0030] Various embodiments of the present disclosure will now be
described with reference to the appended drawings. It is to be
appreciated that these drawings depict only some embodiments of the
disclosure and are therefore not to be considered limiting of its
scope.
DETAILED DESCRIPTION
[0031] As used herein in connection with prosthetic heart valves,
the term "proximal" refers to the end of the heart valve closest to
the heart when the heart valve is implanted in a patient, whereas
the term "distal" refers to the end of the heart valve farthest
from the heart when the heart valve is implanted in a patient. When
used in connection with devices for delivering a prosthetic heart
valve into a patient, the terms "proximal" and "distal" are to be
taken as relative to the user of the delivery devices. "Proximal"
is to be understood as relatively close to the user, and "distal"
is to be understood as relatively farther away from the user.
[0032] FIG. 1 shows a collapsible prosthetic heart valve 200
according to the prior art. The prosthetic heart valve 200 is
designed to replace the function of a native aortic valve of a
patient. Examples of collapsible prosthetic heart valves are
described in International Patent Application Publication No.
WO/2009/042196; and U.S. Pat. Nos. 7,018,406 and 7,329,278, the
disclosures of all of which are hereby incorporated herein by
reference. As discussed in detail below, the prosthetic heart valve
has an expanded condition, shown in FIG. 1, and a collapsed
condition. Although the delivery system is described herein in
connection with its use to deliver a prosthetic heart valve for
replacing a native aortic valve, the delivery system is not so
limited, and may be used to deliver prosthetic valves for replacing
other types of native or prosthetic cardiac valves.
[0033] Prosthetic heart valve 200 includes an expandable stent 202
which may be formed from any biocompatible material, such as
metals, synthetic polymers or biopolymers capable of functioning as
a stent. Stent 202 extends from a proximal or annulus end 230 to a
distal or aortic end 232, and includes an annulus section 240
adjacent the proximal end and an aortic section 242 adjacent the
distal end. The annulus section 240 has a relatively small
cross-section in the expanded condition, while the aortic section
242 has a relatively large cross-section in the expanded condition.
Preferably, annulus section 240 is in the form of a cylinder having
a substantially constant diameter along its length. A transition
section 241 may taper outwardly from the annulus section 240 to the
aortic section 242. Each of the sections of the stent 202 includes
a plurality of cells 212 connected to one another in one or more
annular rows around the stent. For example, as shown in FIG. 1, the
annulus section 240 may have two annular rows of complete cells 212
and the aortic section 242 and transition section 241 may each have
one or more annular rows of partial cells 212. The cells 212 in the
aortic section 242 may be larger than the cells 212 in the annulus
section 240. The larger cells in the aortic section 242 better
enable the prosthetic valve 200 to be positioned without the stent
structure interfering with blood flow to the coronary arteries.
[0034] Stent 202 may include one or more retaining elements 218 at
the distal end 232 thereof, the retaining elements being sized and
shaped to cooperate with female retaining structures provided on
the deployment device. The engagement of retaining elements 218
with the female retaining structures on the deployment device helps
maintain prosthetic heart valve 200 in assembled relationship with
the deployment device, minimizes longitudinal movement of the
prosthetic heart valve relative to the deployment device during
unsheathing or resheathing procedures, and helps prevent rotation
of the prosthetic heart valve relative to the deployment device as
the deployment device is advanced to the target location and during
deployment.
[0035] The prosthetic heart valve 200 includes a valve assembly 204
positioned in the annulus section 240. Valve assembly 204 includes
a cuff 206 and a plurality of leaflets 208 which collectively
function as a one-way valve. The commissure between adjacent
leaflets 208 may be connected to commissure features 216 on stent
202. FIG. 1 illustrates a prosthetic heart valve for replacing a
native tricuspid valve, such as the aortic valve. Accordingly,
prosthetic heart valve 200 is shown in FIG. 1 with three leaflets
208, as well as three commissure features 216. As can be seen in
FIG. 1, the commissure features 216 may lie at the intersection of
four cells 212, two of the cells being adjacent one another in the
same annular row, and the other two cells being in different
annular rows and lying in end-to-end relationship. Preferably,
commissure features 216 are positioned entirely within annulus
section 240 or at the juncture of annulus section 240 and
transition section 241. Commissure features 216 may include one or
more eyelets which facilitate the suturing of the leaflet
commissure to the stent. However, it will be appreciated that the
prosthetic heart valves may have a greater or lesser number of
leaflets and commissure features. Additionally, although cuff 206
is shown in FIG. 1 as being disposed on the luminal surface of
annulus section 240, it is contemplated that the cuff may be
disposed on the abluminal surface of annulus section 240, or may
cover all or part of either or both of the luminal and abluminal
surfaces of annulus section 240. Both the cuff 206 and the leaflets
208 may be wholly or partly formed of any suitable biological
material or polymer.
[0036] In operation, a prosthetic heart valve, including the
prosthetic heart valve described above, may be used to replace a
native heart valve, such as the aortic valve, a surgical heart
valve or a heart valve that has undergone a surgical procedure. The
prosthetic heart valve may be delivered to the desired site (e.g.,
near a native aortic annulus) using any suitable delivery device,
including the delivery devices described in detail below. During
delivery, the prosthetic heart valve is disposed inside the
delivery device in the collapsed condition. The delivery device may
be introduced into a patient using a transfemoral, transapical or
transseptal approach. Once the delivery device has reached the
target site, the user may deploy the prosthetic heart valve. Upon
deployment, the prosthetic heart valve expands into secure
engagement within the native aortic annulus. When the prosthetic
heart valve is properly positioned inside the heart, it works as a
one-way valve, allowing blood to flow in one direction and
preventing blood from flowing in the opposite direction.
[0037] In a prosthetic heart valve, the valve assembly may be
spaced from the distal or aortic end of the stent by a distance
that enables deployment of the heart valve by an amount sufficient
for the valve leaflets of the prosthetic valve to operate as
intended, while the distal end of the stent remains captured by the
delivery device. More particularly, as will be explained further
below, the annulus end of the prosthetic heart valve may be
deployed first, while the aortic end of the prosthetic heart valve
remains at least partially covered by a distal sheath of the
delivery device. The annulus portion of the prosthetic heart valve
may be deployed so that the entirety of the valve leaflets, up to
and including the commissures, is deployed and fully operational.
By deploying the prosthetic heart valve in this manner, the user
can determine whether the valve leaflets are properly positioned
relative to the native valve annulus, and whether the valve is
functioning properly. If the user determines that the positioning
and operation of the valve are acceptable, the remainder of the
valve may be deployed. However, if it is determined that the
leaflet position is improper or that the valve is not functioning
properly, the user may resheathe the valve and either reposition it
for redeployment, or remove it entirely from the patient. This can
be particularly important in very high risk patients who would
typically be recipients of these types of valves because of the
nature of their condition and the impact that may have on the shape
and/or condition of the native valve and valve annulus.
[0038] As is shown in FIG. 1, in one embodiment the entirety of
valve assembly 204, including the leaflet commissures, is
positioned in the annulus section 240 of stent 202. When opened,
the leaflets may extend further into the transition section 241 or
may be designed such that they remain substantially completely
within the annulus section. That is, substantially the entirety of
valve assembly 204 is positioned between the proximal end 230 of
stent 202 and the commissure features 216, and none of the valve
assembly 204 is positioned between commissure features 216 and the
distal end 232 of the stent. Indeed, in some embodiments, the valve
can be designed such that, upon partial deployment, the commissure
features are fully exposed, oriented generally parallel to the
direction of blood flow, and at or near their actual radially
expanded positions (but not necessarily their eventual positions
relative to the annulus), such that the leaflets can operate
substantially as they would when the valve is fully deployed, even
though enough of the stent is still retained within the delivery
device or sheath to permit resheathing.
[0039] In a preferred arrangement, the distance between commissure
features 216 and the distal end 232 of stent 202 will be about
two-thirds of the length of the stent from the proximal end 230 to
the distal end. This structural arrangement provides advantages in
the deployment of prosthetic valve 200 as will be discussed in more
detail with reference to FIGS. 2A and 2B. By having the entirety of
valve assembly 204 positioned within annulus section 240, and by
having a sufficient distance between commissure features 216 and
the distal end 232 of stent 202, the valve assembly and commissures
will not impede blood flow into the coronary arteries and will not
interfere with access thereto during cardiac intervention, such as
angiography, annuloplasty or stent placement.
[0040] Further, it is possible to partially deploy prosthetic valve
200 so that the valve assembly 204 thereof is able to fully
function in its intended position in the native valve annulus,
while a sufficient amount of the aortic section 242 is retained
within the delivery device should resheathing become necessary. In
other words, as will be explained in more detail below, the user
may withdraw the distal sheath of the delivery device to gradually
expose prosthetic valve 200, beginning at the proximal end 230.
Continued withdrawal of the distal sheath will expose a greater
extent of the prosthetic valve until the entire annulus section 240
and valve assembly 204 have been exposed. Upon exposure, these
portions of the prosthetic valve will expand into engagement with
the native valve annulus, entrapping the native valves, except for
a small portion immediately adjacent the free end of the distal
sheath which will be constrained by the distal sheath from fully
expanding.
[0041] However, once the distal sheath has been withdrawn to expose
a sufficient portion of the aortic section 242, the annulus section
240 will be able to fully expand and valve assembly 204 will be
able to function in the same manner as if the entirety of
prosthetic valve 200 had been deployed. At this juncture, it will
be possible for the user to ascertain whether annulus section 240
and valve assembly 204 have been properly positioned relative to
the native valve annulus, and whether the valve assembly is
functioning properly.
[0042] If the position and operation of valve assembly 204 are
acceptable, the distal sheath may be withdrawn further to deploy
the remainder of prosthetic valve 200. On the other hand, if the
positioning or operation of valve assembly 204 are unacceptable,
the user may advance the distal sheath to resheathe the prosthetic
valve, reposition the valve and initiate the deployment procedure
anew. And if it is determined that the valve is not functioning
properly, it can be withdrawn from the patient and a new valve
introduced.
[0043] It will be appreciated from the foregoing that the placement
of the leaflets 208 within the stent 202 can affect the valve
functioning during partial deployment. FIG. 2A illustrates a valve
assembly 204 with high placement, while FIG. 2B illustrates a valve
assembly with low placement. As used herein, the phrase "high
placement" of a valve assembly refers to locating the valve
assembly within the transition section 241 of the stent 202, or
within the portion of the annulus section 240 closest to the
transition section. The phrase "low placement" of a valve assembly
refers to locating the valve assembly closer to the proximal end
230 of the stent 202 and entirely within the annulus section 240
thereof, such that the leaflets 208 are substantially disposed
within the annulus section.
[0044] As seen in FIG. 2A, during partial deployment the annulus
end of the heart valve 200 is unsheathed and allowed to expand. The
distal end 232, including the aortic section 242, remains partially
sheathed and coupled to the delivery device. Operation of the
delivery device is described below in more detail with reference to
FIGS. 3A-7B. Turning back to FIG. 2A, it will be appreciated that
high placement of valve assembly 204 will cause the valve assembly
to not be fully deployed when heart valve 200 is only partially
deployed, thereby affecting leaflet function. Specifically, since
the commissure features 216 are located closer to or within the
transition section 241, they do not reach their fully expanded
positions. As such, the leaflets 208 remain partially closed at
this stage of deployment. Because of the location of the commissure
features 216 and the leaflets 208, the valve assembly 204 cannot be
tested during partial deployment. Instead, the user must unsheathe
a portion of the aortic section 242 as well, which may pose
problems if the valve assembly 204 is to be resheathed and
redeployed.
[0045] In contrast to the prosthetic heart valve of FIG. 2A, the
heart valve 200 of FIG. 2B exhibits low placement of the valve
assembly 204 within the annulus section 240. Low placement of the
valve assembly 204 enables the valve assembly to fully deploy when
heart valve 200 is only partially deployed. As such, leaflets 208
reach their fully expanded and open positions during partial
deployment and are able to function near normally, enabling a
better assessment of the valve's functioning and final placement
within the actual anatomy. Thus, if it appears that the valve needs
to be moved, the heart valve 200 may be easily resheathed and
repositioned. This concept is beneficial when dealing with less
than ideal anatomical configurations.
[0046] The shape of the stent 202 during partial deployment will
also affect the valve 204. If the stent shape is such that, while
still partially retained by the sheath, it cannot open sufficiently
to allow operation of the valve, it may not be possible to fully
assess the operation of the valve in its intended placement
position. Moreover, the height of the valve commissure features 216
relative to the proximal end 230 of the valve will affect the valve
function. The lower the commissure features 216, meaning the closer
to the proximal end 230, the more they will expand outwardly and
the valve leaflets will be able to open during partial deployment,
creating a flow passageway through the leaflets which approaches
that of a fully deployed valve.
[0047] A transfemoral or transapical delivery device may be used to
partially deploy the prosthetic heart valve such that an assessment
may be made regarding flow through the valve and adequacy of
coaptation. If, after the annulus section is unsheathed and the
valve is tested, it is found that the valve needs to be
repositioned, the annulus section may be resheathed and the valve
redeployed as necessary.
[0048] Turning now to FIGS. 3A-D, an exemplary transfemoral
delivery device 1010 for a collapsible prosthetic heart valve (or
other types of self-expanding collapsible stents) has a catheter
assembly 1016 for delivering the heart valve to and deploying the
heart valve at a target location, and an operating handle 1020 for
controlling deployment of the valve from the catheter assembly. The
delivery device 1010 extends from a proximal end 1012 to a distal
tip 1014. The catheter assembly 1016 is adapted to receive a
collapsible prosthetic heart valve (not shown) in a compartment
1023 defined around an inner shaft 1026 and covered by a distal
sheath 1024. The inner shaft 1026 extends through the operating
handle 1020 to the distal tip 1014 of the delivery device, and
includes a retainer 1025 affixed thereto at a spaced distance from
distal tip 1014 and adapted to hold a collapsible prosthetic valve
in the compartment 1023.
[0049] The distal sheath 1024 surrounds the inner shaft 1026 and is
slidable relative to the inner shaft such that it can selectively
cover or uncover the compartment 1023. The distal sheath 1024 is
affixed at its proximal end to an outer shaft 1022, the proximal
end of which is connected to the operating handle 1020 in a manner
to be described. The distal end 1027 of the distal sheath 1024
abuts the distal tip 1014 when the distal sheath fully covers the
compartment 1023, and is spaced apart from the distal tip 1014 when
the compartment 1023 is at least partially uncovered.
[0050] The operating handle 1020 is adapted to control deployment
of a prosthetic valve located in the compartment 1023 by permitting
a user to selectively slide the outer shaft 1022 proximally or
distally relative to the inner shaft 1026, or to slide the inner
shaft 1026 relative to the outer shaft 1022, thereby respectively
uncovering or covering the compartment with the distal sheath 1024.
Operating handle 1020 includes frame 1030 which extends from a
proximal end 1031 to a distal end and includes a top frame portion
1030a and a bottom frame portion 1030b. The proximal end of the
inner shaft 1026 is coupled to a hub 1100, and the proximal end of
the outer shaft 1022 is affixed to a carriage assembly 1040 (FIG.
4) that is slidable within the operating handle along a
longitudinal axis of the frame 1030, such that a user can
selectively slide the outer shaft relative to the inner shaft by
sliding the carriage assembly relative to the frame. Alternatively,
inner shaft 1026 may be actuated via hub 1100 to cover or uncover
the compartment as will be discussed in greater detail below.
Optionally, a stability sheath 1051 is disposed over some or all of
outer shaft 1022. The stability sheath 1051 may be attached to the
outer shaft 1022 or may be unattached. Additionally, stability
sheath 1051 may be disposed over a majority of outer shaft 1022 or
over a minority of the outer shaft (e.g., over 49% or less, over
33%, etc.). Optionally, stability sheath 1051 may be more rigid
than outer shaft 1022.
[0051] Additionally, hub 1100 may include a pair of buttons 1610,
each attached to a clip 1612 (FIG. 3D). Clips 1612 on hub 1100 may
mate with voids 1614 on frame 1030 to ensure that the hub and the
frame are securely coupled together. Optionally, hub 1100 may also
include a wheel 1600, which will be described in greater detail
below.
[0052] A first mechanism for covering and uncovering the
compartment 1023 will be referred to as a "fine" technique as
covering and uncovering occurs slowly with a high degree of
precision. To allow for this technique, frame 1030 defines an
elongated space 1035 in which carriage assembly 1040 may travel
(FIG. 5). The elongated space preferably permits the carriage
assembly 1040 to travel a distance that is at least as long as the
anticipated length of the prosthetic valve to be delivered (e.g.,
at least about 50 mm), such that the distal sheath 1024 can be
fully retracted off of the prosthetic valve.
[0053] The carriage assembly 1040 includes a main body 1041 and a
threaded rod 1036 extending proximally therefrom along the
longitudinal axis of the frame 1030. The threaded rod 1036
preferably is longer than the anticipated maximum travel distance
of the carriage assembly 1040 within the elongated space 1035
(e.g., at least about 50 mm), such that the threaded rod does not
fully withdraw from the elongated space 1035 during deployment of
the prosthetic valve.
[0054] A deployment actuator 1021, shown in FIGS. 3A-D as a wheel
protruding from the upper and lower frames 1030a,1030b is fixedly
coupled to a first gear 1037 so that rotation of actuator 1021
causes a corresponding rotation of gear 1037. Gear 1037, in turn,
is threadedly engaged on the threaded rod 1036. Gear 1037 converts
rotation of deployment actuator 1021 into longitudinal translation
of threaded rod 1036 in the direction of arrows T1 and T2 and a
corresponding translation of main body 1041. Hence, rotation of
actuator 1021 in one direction (either clockwise or
counterclockwise depending on the orientation of the threads on the
threaded rod 1036) causes the carriage assembly 1040 to translate
proximally in direction T1 within the elongated space 1035.
Alternatively, actuator 1021 and first gear 1037 may be integral
with one another.
[0055] As outer shaft 1022 is fixedly connected to carriage
assembly 1040, translation of the carriage assembly results in a
longitudinal translation of outer shaft 1022 and with it distal
sheath 1024. Thus, deployment actuator 1021 is configured to
provide for fine movement of outer shaft 1022 for deployment and
recapture of the prosthetic heart valve. As deployment actuator
1021 protrudes from upper and lower frames 1030a,1030b
approximately halfway between the proximal and distal ends of the
handle 1020, a user may readily rotate the actuator with his or her
thumb and/or index finger (FIG. 7A).
[0056] Optionally, handle 1020 further includes a resheathing lock
1043 adapted to prevent any movement of the carriage assembly
within the frame 1030, thereby preventing a user from accidentally
initiating deployment of a prosthetic valve (FIG. 3C). Resheathing
lock 1043 may be coupled to the main body 1041 of carriage assembly
1040. The resheathing lock 1043 may include a laterally projecting
pin 1044 that is slidable within a hole 1046 in main body 1041. Pin
1044 may have a first or unlocked condition in which it is
compressed between main body 1041 and frame 1030.
[0057] As the user rotates deployment actuator 1021, outer shaft
1022 is pulled back and with it distal sheath 1024 to uncover a
portion of compartment 1023. This process may continue until a
predetermined position just prior to a position at which
resheathing is no longer possible. When this predetermined position
is reached, a spring 1045 positioned in hole 1046 between main body
1041 and pin 1044 pushes the pin out through an aperture in frame
1030 to a second or locked condition (FIG. 5) in which the pin
protrudes from frame 1030, providing a visual indicator to the user
that resheathing is no longer possible past this predetermined
position. Further translation of the carriage assembly 1040 may be
impeded until the user presses pin 1044 to the interior of frame
1030 against the action of spring 1045 to confirm that further
uncovering of compartment 1023 is desired (i.e., that the user
wishes to fully deploy the prosthetic heart valve in its current
position).
[0058] The initial distance that the carriage assembly 1040 can
travel before actuating resheathing lock 1043 may depend on the
structure and size of the particular prosthetic valve to be
deployed. Preferably, the initial travel distance of the carriage
assembly 1040 is about 3 mm to about 5 mm less than the length of
the valve in the collapsed condition (e.g., about 3 mm to about 5
mm of the valve may remain covered to permit resheathing).
Alternatively, the initial travel distance of the carriage assembly
1040 may be about 40 mm to about 45 mm, which is about 80% to about
90% of the length of an exemplary 50 mm valve. In other
arrangements, the initial distance that the carriage assembly 1040
can travel can be determined as a percentage of the length of the
prosthetic valve in the collapsed condition and/or of the
compartment 1023, including, for example, 50%, 60%, 70%, 75%, 85%,
95% or anywhere between about 50% and about 95%. Thus, resheathing
lock 1043 may allow uncovering of compartment 1023 up to a maximum
distance or percentage, and allow further uncovering only after the
user has pressed on laterally projecting pin 1044 to confirm that
additional release (e.g., full release of the prosthetic heart
valve) is desired.
[0059] A second technique, referred to as a "coarse technique," may
be used to cover and uncover compartment 1023 more quickly and with
less precision than the fine technique described above.
Specifically, hub 1100 may be coupled to the proximal end of inner
shaft 1026 and may be capable of moving the inner shaft relative to
frame 1030 to facilitate opening and closing of the compartment
1023. This coarse movement may be used when no prosthetic heart
valve is present in the compartment, such as, for example, when the
compartment is to be opened prior to loading the prosthetic heart
valve, and when the compartment is to be closed after the valve has
been fully deployed. A mechanical lock 1110 may couple hub 1100 to
frame 1030 to prevent accidental movement during use of operating
handle 1020. For example, hub 1100 and a portion of frame 1030 may
be threadedly engaged such that a rotation of the hub relative to
the frame is required to release the hub from the frame. Other
types of mechanical locks that will releasably couple hub 1100 to
frame 1030 as intended will be known to those skilled in the art.
After lock 1110 has been disengaged, hub 1100 may be used to
quickly cover or uncover compartment 1023. Movement of inner shaft
1026 with respect to outer shaft 1022 may open and close the
compartment. Thus, pushing hub 1100 distally (and thus the distal
movement of inner shaft 1022) opens compartment 1023 and pulling
hub 1100 proximally closes the compartment.
[0060] Optionally, an indicator window 1500 (FIG. 6) may be
disposed on top of frame 1030 and may include a series of
increments 1510 showing a percent or extent of deployment of the
prosthetic heart valve. A scrolling bar 1520 may move along window
1500 past the series of increments 1510 as deployment continues to
illustrate to the user the extent to which the prosthetic heart
valve has been deployed. As illustrated, scrolling bar 1520
indicates that a prosthetic heart valve is approximately 37.5%
deployed. Indicator window 1500 further includes a critical
indicator 1530 showing the position past which resheathing is no
longer possible. Resheathing lock 1043 may be activated as
scrolling bar 1520, which is coupled to the main body 1041 of
carriage assembly 1040 reaches position 1530.
[0061] The general operation of the delivery device 1010 to deploy
a prosthetic valve will now be described. Device 1010 may be
shipped with outer shaft 1022 in its proximal-most position. Hub
1100 may also be initially shipped in a proximal-most position, the
hub being spaced away from frame 1030. (FIG. 7B) However,
compartment 1023 will be covered by distal sheath 1024. To load the
delivery device 1010 with a collapsible prosthetic valve, a user
can push hub 1100 distally (and advance inner shaft 1026) to expose
the compartment 1023 (FIG. 7A), thread the inner shaft 1026 through
the valve, collapse the valve and couple it to a retainer, and
rotate deployment actuator 1021 to advance the distal sheath back
over compartment 1023 to fully cover the valve. In this starting
condition, the handle 1020 will be in an initial state with the
carriage assembly 1040 at its distalmost position within the frame
1030, the resheathing lock 1043 will be in an unlocked state with
pin 1044 disposed within frame 1030, the hub 1100 will be in its
distal-most position and coupled to frame 1030, and the deployment
indicator will show 0% deployment.
[0062] To use the operating handle 1020 to deploy the prosthetic
valve, the user can rotate the deployment actuator 1021, causing
the carriage assembly 1040 to slide proximally within the elongated
space 1035 in frame 1030. Because the distal sheath 1024 is affixed
to the outer shaft 1026, which in turn is affixed to the carriage
assembly 1040, sliding the carriage assembly proximally relative to
the frame will cause the distal sheath to move proximally. Since
the inner shaft 1026 is at this point fixed to frame 1030, it will
not move. Hence, the proximal movement of distal sheath 1024
relative to inner shaft 1022 will uncover the compartment 1023,
thereby exposing and initiating deployment of the valve located
therein.
[0063] Movement of the carriage assembly 1040 proximally may
continue only until the resheathing lock 1043 is actuated and pin
1044 protrudes from frame 1030. At this point, the distal sheath
1024 will not be fully withdrawn from around the compartment 1023,
and the prosthetic valve will not be fully deployed. Moreover,
indicator window 1500 will show that scrolling bar 1520 has reached
critical indicator 1530 and that any further uncovering of the
compartment will fully deploy the prosthetic heart valve and
prevent its resheathing.
[0064] When the deployment procedure has reached this juncture, the
user can evaluate the position of the valve and determine whether
the annulus end of the valve is properly aligned relative to the
patient's native valve annulus. If repositioning is desired, the
user may resheathe the valve by using deployment actuator 1021 to
slide the carriage assembly 1040 distally within the frame 1030,
thereby moving the distal sheath 1024 distally over the compartment
1023 and over the partially deployed valve to recollapse the
expanded portion of the valve. With the valve resheathed, the user
can reposition the catheter assembly 1016 and commence the
deployment procedure once again.
[0065] Once the valve has been properly positioned relative to the
aortic annulus, the user may complete the deployment process. To do
so, the user presses pin 1044 through the aperture in frame 1030,
releasing lock 1043, which frees carriage assembly 1040 to continue
its movement proximally within the frame. The user can complete the
deployment of the valve by continuing to slide the carriage
assembly 1040 proximally, for example, by rotating the deployment
actuator 1021. When the valve has been fully unsheathed, the stent
portion of the valve self-expands and disengages from the retainer
1025, thereby releasing the valve from the catheter assembly 1016,
following valve deployment, hub 1100 may once again be used to
quickly cover the compartment and the delivery device may be
removed from the patient.
[0066] Three additional features may be added to the delivery
device 1010 described above to improve the performance of the
device. It will be understood that all three of these features are
optional, and that the delivery device may include none of the
features, one of the features, or a combination of the features as
desired. The three features are the optional use of a second wheel
for gap closure, a robust resheathing lock mechanism, and an
actuator clutch mechanism. Each will be described, in turn, with
reference to FIGS. 8-10.
[0067] FIGS. 8A-C illustrate the use of additional features on the
hub 1100 to aid in valve loading and delivery. As discussed, the
delivery device 1010 may be packaged with the hub 1100 withdrawn to
the proximal position and the deployment actuator 1021 turned such
that the distal sheath 1024 is in its proximal position, leaving a
closed capsule (see FIG. 3A). Hub 1100 may be moved distally to
move inner shaft 1026 to its distal position and thus open the
compartment 1023 for valve loading. After the valve has been
loaded, actuator 1021 may be rotated to move the distal sheath 1024
over the valve and close the compartment 1023. The delivery device
1010 is designed such that the distal end 1027 of the distal sheath
1024 abuts the distal tip 1014 when the distal sheath fully covers
the compartment 1023, and is spaced apart from the distal tip 1014
when the compartment 1023 is at least partially uncovered.
[0068] As shown in FIG. 8A, in some circumstances, though the
actuator 1021 has been properly used to close the compartment 1023,
the distal end 1027 of the distal sheath 1024 may not abut the
distal tip 1014, leaving a gap g1 between the distal end of the
sheath and the distal tip 1014. This gap may be due to residual
compression in distal sheath 1024 and/or frictional forces between
distal sheath 1024 and the loaded prosthetic heart valve. In
effect, though distal sheath 1024 has been fully moved to its
distal-most position with respect to the shaft 1026, it may be
slightly bunched together and not fully extended, leaving gap
g1.
[0069] To close the gap g1, a second wheel 1600 may be used, the
details of which are shown in FIGS. 8B-C. Wheel 1600 may be
disposed in hub 1100 and mounted over cam 1605 having threaded
portion 1606, cam 1605 in turn being coupled to inner shaft 1026.
Turning wheel 1600 while holding frame 1030 may pull cam 1605, and
thus inner shaft 1026, proximally to close the gap g1 and force the
distal end 1027 of distal sheath 1024 to abut distal tip 1014 (FIG.
8C). Once the gap g1 is closed, wheel 1600 may be rotated in the
opposite direction to relieve any tension within the distal sheath
1024 (FIG. 8B). A flange 1607 on cam 1605 may contact wheel 1600
and create a hard stop position when returning inner shaft 1026 to
a neutral position. In some embodiments, wheel 1600 allows for
translation of shaft 1026 by between about 0.25 inch and about 1
inch relative to distal sheath 1024.
[0070] FIGS. 9A-G illustrate another example of a resheathing lock
mechanism 1700. As shown in FIGS. 9A-B, resheathing lock mechanism
1700 generally includes a lock body 1701 having of two ribs that
face one another and lock finger 1702 that sits on compression
spring 1703 and protrudes from the lock body in the distal
direction. Lock body 1701 is coupled to lock arms 1704, which in
turn are coupled to a lock button 1705 that protrudes from frame
1030. A dowel hinge pin 1707 pivotally connects lock body 1701 to
frame 1030. A leaf spring 1706 extending from the base of lock body
1701 and fixed to the frame 1030 is configured to apply a constant
upward force to lock body 1701.
[0071] As shown in FIGS. 9C-D, ribs of the lock body 1701 are
disposed in elongated slots 1710 formed on opposite sides of
threaded rod 1036. As the actuator 1021 is operated to move
carriage assembly 1040 with respect to lock mechanism 1700, the
ribs ride along slots 1710 in the threaded rod 1036. At or near the
distal end of the threaded rod 1036, each of the slots includes a
ramp 1711 that angles upward toward the upper portion of frame 1030
(not shown). As the carriage assembly 1040 and threaded rod 1036
move proximally, the ribs of lock body 1701 continue to ride along
the slots 1710 in threaded rod 1036 and up ramp 1711 as the lock
body is urged to pivot upward by leaf spring 1706 (FIG. 9D).
[0072] The upward movement of the lock body 1701 moves lock finger
1702 upward toward carriage assembly 1040, wherein it is eventually
received in a cavity 1715 formed in the carriage assembly (FIG.
9E). As the carriage assembly continues to move proximally with
rotation of the actuator 1021, lock finger 1702 contacts an end
wall of cavity 1715 such that for the retraction of the carriage
assembly gradually compresses spring 1703. When spring 1703 is
fully compressed, carriage assembly 1040 is mechanically locked
against further travel (FIG. 9F). This locked position corresponds
to the point past which resheathing of the heart valve is no longer
possible. The user may test functionality of the valve at this
point, resheathe and re-implant the valve, or remove the prosthetic
heart valve entirely. If the physician decides to continue the
procedure and release the valve entirely, lock button 1705 may be
depressed, pivoting the lock body 1701 and lock finger 1702
downward until lock finger 1702 no longer contacts the end wall of
cavity 1715. At this point, spring 1703 may force lock finger 1702
outward and below carriage assembly 1040, releasing the carriage
assembly for further proximal movement (FIG. 9G).
[0073] The actuator 1021 of the delivery device 1010 may also
include a clutch mechanism so that when the resheathing lock 1700
is engaged, if the user continues to rotate the actuator a clutch
between the actuator and the threaded rod 1036 prevents damage to
the device. FIG. 10A shows one example of a clutch mechanism for
use with actuator 1021. As shown, a clutch plate 1804 is assembled
in a shell 1801 of actuator 1021 with a compression spring 1805
disposed between the clutch plate and the shell. In its assembled
position, features (not shown) on the clutch plate 1804 engage with
corresponding features (not shown) in the interior of shell 1801 to
rotationally lock the clutch plate to the shell but permit the
clutch plate to move axially within the shell. A drive nut 1803 is
positioned adjacent clutch plate 1804, and the entire assembly is
enclosed by a wheel cap 1802. A pair of assembly screws 1806
assemble the wheel cap 1802 to the wheel shell 1801 to hold the
assembly together. Drive nut 1803 is internally threaded so that
the fully assembled actuator 1021 may be threaded onto threaded rod
1036. Drive nut 1803 is not rotationally locked to shell 1801 but
rather is freely rotatable relative to same. A cross-sectional view
of the assembled actuator 1021 mounted on threaded rod 1036 is
shown in FIG. 10B.
[0074] Details of drive nut 1803 and clutch plate 1804 will be
described in greater detail with reference to FIGS. 10C and 10D.
Drive nut 1803 includes a plurality of directional teeth 1813
around its circumference, each tooth having a sloped portion 1814
and a generally perpendicular portion 1815. The teeth 1813 on drive
nut 1803 confront a plurality of complementary directional teeth
1816 positioned around the circumference of clutch plate 1804.
Directional teeth 1816 have a similar configuration to the teeth
1813 of the drive nut 1803 so that the teeth are able to mesh with
one another. When a predetermined axial force is reached upon
rotation of the actuator 1021 in the deployment direction, teeth
1813 and 1816 slip relative to one another in a first direction.
Compression spring 1805 applies a constant engagement force to keep
clutch plate 1804 engaged with drive nut 1803 until the
predetermined force is reached. Slippage occurs when a force
greater than the predetermined force is applied, which typically
occurs when the actuator is rotated while the resheathing lock
mechanism 1700 is in the locked position. The predetermined
slippage force may be determined by the angle of the sloped portion
of teeth 1813 and 1816, the height of the teeth (i.e., the height
of the perpendicular portions), spring force of compression spring
1805, and friction between drive nut 1803 and clutch plate
1804.
[0075] In use, resheathing lock mechanism 1700 may be urged toward
the locked positon as described above, preventing the carriage
assembly 1040 from moving further in the proximal direction. As
carriage assembly 1040 is unable to move proximally, drive nut 1803
also will be unable to move as actuator 1021 is rotated in the
direction causing proximal movement of the carriage assembly. The
continued effort to rotate actuator 1021 will eventually result in
the exerting of the predetermined force on the actuator. When this
force is reached, the rotational force on the wheel shell 1801 will
drive the clutch plate teeth 1816 up the sloped portion 1814 of the
teeth of the drive nut 1803, moving the clutch plate 1804 axially
until the teeth slip relative to one another. Thus, wheel shell
1801 will be allowed to rotate without any movement of carriage
assembly 1040 and without exerting excessive force on the
resheathing lock mechanism 1700 that could potentially damage same.
In effect, this clutch mechanism serves to limit the amount of
force that the user can apply to the resheathing lock mechanism
1700 and also provides a user input that the partial deployment
limit has been reached when the user senses that the wheel is
turning but no further actuation results. During re-sheathing of
the valve, where the forces on the catheter are highest, in a
direction opposite the first direction, the teeth are engaged in
such a manner as to prevent any slippage of the clutch due to the
presence of generally perpendicular portions 1815 on the teeth.
[0076] FIGS. 11A-E illustrate another example of a resheathing lock
mechanism 1900, which is a variation of the resheathing lock
mechanism 1700 shown in FIGS. 9A-G. The resheathing lock mechanism
1900 has an identical structure and function to the resheathing
lock mechanism 1700, except for the differences that are described
below. As shown in FIGS. 11A-B, resheathing lock mechanism 1900
generally includes a lock body 1910 having two ribs 1901 that face
one another and lock finger 1902 that sits on compression spring
1903 and protrudes from the lock body in the distal direction. Lock
body 1910 is coupled to lock arms 1904, which in turn are coupled
to a lock button 1905 that is configured to protrude through an
opening in frame 1030 when in a locked condition. A dowel hinge pin
1907 pivotally connects lock body 1910 to frame 1030. A compression
spring 1906 (e.g., a coil spring) extending from the base of lock
body 1910 and fixed to frame 1030 is configured to apply a constant
upward force to lock body 1910. In some embodiments, a torsion
spring may be used in place of compression spring 1906.
[0077] As shown in FIGS. 11C-D, ribs 1901 of the lock body 1910
maintain contact with the bottom of threaded rod 1036 due to the
force provided by compression spring 1906. As actuator 1021 is
operated to move carriage assembly 1040 and threaded rod 1036 with
respect to lock mechanism 1900, the threads of the threaded rod
slide along ribs 1901, with the ribs oriented transverse (e.g.,
80.degree.-85.degree.) to the threads. At or near the distal end of
threaded rod 1036, the threaded rod defines a cavity 1915 formed in
the bottom of carriage assembly 1040. Cavity 1915 defines a ramp
1911 (FIG. 11E) that angles upward toward the upper portion of
frame 1030 (not shown). As the carriage assembly 1040 and threaded
rod 1036 move proximally, ribs 1901 of lock body 1910 continue to
ride along the bottom of threaded rod 1036 and up ramp 1911 as the
lock body is urged to pivot upward about dowel hinge pin 1907 by
compression spring 1906.
[0078] The upward pivoting of the front of lock body 1910 moves
lock finger 1902 upward toward carriage assembly 1040, wherein it
is eventually received in cavity 1915. As carriage assembly 1040
continues to move proximally with the rotation of actuator 1021,
lock finger 1902 contacts an end wall of cavity 1915 such that
continued proximal translation of the carriage assembly gradually
compresses spring 1903. When spring 1903 is fully compressed,
carriage assembly 1040 is mechanically locked against further
proximal travel (FIG. 11E). This locked position corresponds to the
point past which resheathing of the heart valve is no longer
possible. The user may test functionality of the valve at this
point, resheathe and re-implant the valve, or remove the prosthetic
heart valve entirely. If the physician decides to continue the
procedure and release the valve entirely, lock button 1905 may be
depressed, pivoting lock body 1910 and lock finger 1902 downward
until the lock finger no longer contacts the end wall of cavity
1915. At this point, spring 1903 forces lock finger 1902 distally
below carriage assembly 1040, releasing the carriage assembly for
further proximal movement, in a manner similar to that shown in
FIG. 9G.
[0079] In some examples, a delivery device for a collapsible
prosthetic heart valve, the delivery device includes an inner
shaft, a distal sheath disposed about a portion of the inner shaft
to form a compartment with the inner shaft, the compartment being
sized to receive the prosthetic heart valve, the inner shaft and
the distal sheath being movable relative to one another, and a
handle including a frame having a longitudinal axis, a deployment
actuator operatively connected to the distal sheath, and a hub
operatively connected to the inner shaft, each of the deployment
actuator and the hub being independently capable of opening and
closing the compartment, the hub further including a hub actuator
coupled to the inner shaft; and/or the deployment actuator includes
a first wheel having an axis of rotation disposed parallel to the
longitudinal axis of the frame, and the hub actuator includes a
second wheel having an axis of rotation that is parallel to the
axis of rotation of the first wheel; and/or the second wheel is
engaged with a translating cam having a threaded portion, the cam
being coupled to the inner shaft; and/or the cam includes a flange
that is perpendicular to the axis of rotation of the second wheel;
and/or the cam is capable of translating between about 0.25 inches
and about 1 inch in a direction parallel to the axis of rotation of
the second wheel; and/or rotation of the second wheel results in
longitudinally translating the inner shaft; and/or rotation of the
deployment actuator results in longitudinally translating the
distal sheath to cover or uncover the compartment.
[0080] In some examples, a delivery device for a collapsible
prosthetic heart valve, the delivery device includes an inner
shaft, a distal sheath disposed about a portion of the inner shaft
to form a compartment sized to receive the prosthetic heart valve,
the inner shaft and the distal sheath being movable relative to one
another, and a handle including a frame having a longitudinal axis,
a deployment actuator a resheathing lock having a lock body coupled
to a protruding lock finger in contact with a compression spring, a
lock arm coupled to the lock finger, and a lock button coupled to
the lock arm; and/or the lock button has a first position disposed
within the frame, and a second position in which the lock button
protrudes from the frame; and/or the distal sheath is coupled to a
threaded rod, the threaded rod being coupleable to the lock body;
and/or the threaded rod includes a slot having a ramp and the lock
body slides within the slot of the threaded rod; and/or the lock
body has a pair of ribs configured to maintain contact with a
bottom of the threaded rod when the threaded rod translates along
the longitudinal axis of the frame; and/or the lock finger is
configured to be disposed within a cavity of threaded rod in a
first lock condition that prevents distal movement of the distal
sheath, and to be substantially parallel with the threaded rod in a
second unlocked condition that allows distal movement of the distal
sheath; and/or the delivery device further includes a leaf spring
coupled to the lock finger; and/or the leaf spring is configured to
apply a force to the lock body; and/or the delivery device further
includes a compression spring coupled to the lock finger; and/or
the compression spring is configured to apply a force to the lock
body.
[0081] In some examples, a delivery device for a collapsible
prosthetic heart valve, the delivery device includes an inner
shaft, a distal sheath disposed about a portion of the inner shaft
to form a compartment sized to receive the prosthetic heart valve,
the inner shaft and the distal sheath being movable relative to one
another, and a handle including a frame having a longitudinal axis,
and a deployment actuator operatively connected to the distal
sheath, the deployment actuator including a clutch mechanism that
rotationally couples the deployment actuator to the distal sheath
in a first condition and rotationally decouples the deployment
actuator from the distal sheath in a second condition; and/or the
deployment actuator includes a wheel shell, and the clutch
mechanism includes a clutch plate and a drive nut assembled within
the wheel shell; and/or the drive nut includes a plurality of first
teeth, each having a sloped portion; and/or the clutch plate
includes a plurality of second teeth, complementary to the first
teeth, the second teeth being meshed with the plurality of first
teeth of the drive nut; and/or the assembly includes a compression
spring disposed between the wheel shell and the clutch plate, the
compression spring exerting a force pushing the clutch plate
against the drive nut.
[0082] Although the invention herein has been described with
reference to particular embodiments, it is to be understood that
these embodiments are merely illustrative of the principles and
applications of the present invention. It is therefore to be
understood that numerous modifications may be made to the
illustrative embodiments and that other arrangements may be devised
without departing from the spirit and scope of the present
invention as defined by the appended claims.
[0083] It will be appreciated that the various dependent claims and
the features set forth therein can be combined in different ways
than presented in the initial claims. It will also be appreciated
that the features described in connection with individual
embodiments may be shared with others of the described
embodiments.
* * * * *